Radio communications devices are increasingly being used to communicate in multiple RF bands. An example of multiple band RF devices is a device that is able to communicate by using either the 802.11(b) or the 802.11(a) standard. The 802.11(b) standard uses RF signals in the region near 2.4 GHz and the 802.11(a) standard uses RF signals in the region near 5.0 GHz. It is often desirable, especially in small and/or portable devices, to minimize the number of antennas that are used on the device, and using a single antenna to cover multiple bands generally provides savings in size and manufacturing cost.
RF antennas frequently have fragile physical structures that are irregularly shaped. This characteristic increases the difficulty of integrating RF antennas with communications devices. The size of microwave band antennas generally makes it practical to mount a microwave antenna directly on a circuit board within a portable device, but designs to do so are hampered by the fragility of microwave antenna designs and the difficulty of handling microwave antenna structures with automated part placement machinery. Automated circuit board manufacturing processes frequently use Infra-Red Solder Reflow Ovens that require the electronic components being mounted on the board to withstand heat of the oven while staying in place and not deforming. Many microwave antenna structures are either too fragile or not well suited for Solder Reflow Ovens. The use of additional non-conductive material to enclose or otherwise provide a more easily handled “package” can also affect the electrical and radiation performance of the antenna.
Therefore a need exists to overcome the problems with the prior art as discussed above.